The present invention relates to adjusting mechanism particularly for alignment of automobile headlamps, and more specifically relates to an improved assembly and construction of such mechanisms.
Successful modern adjusting mechanism for vehicle headlamps are described for example in U.S. Pat. Nos. 4,674,018, 4,689,725 and 4,893,219. In the described mechanisms, an adjusting screw is coupled to the headlamp housing and extends into a gear box or adjustment mechanism. The adjusting screw is operatively coupled to an adjusting drive shaft which is operated by conventional hand tools. Movement of the adjusting screw is attained by means of a pair of mitered gears and a threaded connection. One gear is coupled to and driven by a drive shaft, while the other gear is operatively associated with the adjusting screw which is held against rotation. As such, rotation of the drive shaft produces linear movement of the drive screw as is well known in the art.
The gear members can be assembled and sealed within the integral adjuster housing, while allowing the drive shaft and adjusting screw components to be assembled at a later time with a variety of shaft and screw lengths as required for different model automobiles. The adjusting screw is prevented from rotating so that its motion is limited to linear translation to pivot the headlamp housing to a desired orientation. Adjustment mechanisms in accordance with the present invention enable improved performance, construction and assembly of automobile headlamps.